Electrical substrates with circuits conventionally are printed circuit boards comprising fabricated dielectric substrates having planar surfaces upon which are etched an array of circuit paths. Certain printed circuit boards are known which are multilayer, in which a conductive layer (or layer of circuit paths) is embedded within the fabricated substrate to perform tasks such as conducting power or providing grounding without requiring surface area or real estate which is more efficiently used by circuit paths for signal transmission.
Recently substrates have begun to enter the market in which a molded plastic substrate has circuit paths plated thereonto after molding such as by catalyzing the surface, masking off areas of the catalyzed surface not desired to be conductive, exposing the nonmasked areas to actinic light such as ultraviolet and thereby activating the catalyst, conveying metal ions to the activated surface which are captured thereby, and then plating to the metal-containing areas a conductive layer of desired thickness by electroless plating or electroplating, or a combination thereof, resulting in a defined circuit pattern. The molding of the plastic substrate enables or facilitates creating integral structures or features on the substrate surface such as projections, recesses, grooves, holes, tapered surface portions and so on.
It is desired to provide a molded circuit substrate with an integral bussing means which does not utilize circuit path means along exposed substrate surface portions.
It is further desired to embed a conductive plane within a molded circuit substrate to which certain conductive areas along the major surfaces are electrically connected, to interconnect and common a plurality of such conductive areas.